How it grew: Smartphone users aren’t the only folks craving a wider rollout of 4G, the speedy next-generation cellular networks touted by the nation’s largest carriers. Wavsys, a staffing and professional services firm that provides clients like T-Mobile with contract engineers to help build and maintain their networks, expects a big boost in business as its customers make the upgrade. “We’re at the calm before the storm,” said COO Joshua Mangerson, whose firm provides talent from project managers to the workers at the cell sites’ base stations.

Wavsys, founded in 2007 by three young telecom veterans (President Sean Yazbeck won the fifth season of The Apprentice), jumped into the market during the wireless industry’s first round of consolidation. Today, the company is looking to grow by diversifying into new markets in the IT field, such as financial services and government. To do so, Wavsys will hire at least 10 full-time staffers this year, a mix of salespeople and recruiters. “We’re at a stage where we can invest back into ourselves,” said Mr. Mangerson.

Although Tom Ellefson, T-Mobile’s Northeast regional vice president of engineering and operations, has a list of 100 contractors he can call, he tends to go with Wavsys first. “They can turn on a dime and be pretty flexible,” he said. “Their people understand our business really well.”